Cumulative Exergy Demand Research Articles

Analyzing sustainability in bread production: a life cycle assessment approach to energy, exergy and environmental footprint.

Bread production is a pivotal component of global nutrition. However, its extensive production imposes significant strain on resources and energy, resulting in substantial environmental consequences. This study focuses on a multidimensional assessment of the environmental sustainability of the bread life cycle as a case study in Iran. By integrating four life cycle assessment (LCA) methods, this research demonstrates a comprehensive analysis of environmental effects, energy consumption, and exergy demand in bread production. It also identifies the hotspot stages and inputs within the bread production chain. Eventually, it proposes strategies for mitigating the environmental impacts in line with sustainable development goals. Data collection involved questionnaires by face-to-face interviews. The LCA evaluation was conducted using SimaPro software. Sustainability analysis was assessed using four different methods: CML, ReCiPe, cumulative energy demand (CED), and cumulative exergy demand (CExD) method, from cradle to bakery gate. The CML method results indicate that the highest environmental impacts are associated with marine aquatic ecotoxicity (157.04 to 193.36 kg 1,4-DB eq), fossil fuel depletion (11.05 to 12.73 MJ), eutrophication (4.20 × 10-3 to 4.70 × 10-3 kg PO4-3eq), acidification (8.09 × 10-3 to 9.16 × 10-3 kg SO2 eq), and global warming (0.61 to 0.69 kg CO2 eq). The ReCiPe method highlights wheat production stages and gas consumption as the most significant contributors to damage in terms of human health, ecosystems, and resource consumption indicators. The CED method reveals that fossil energy accounts for over 97% of the energy consumed during the bread life cycle. Energy consumption per kilogram of bread ranges from 12.07 to 13.93 MJ. The CExD method for producing 1 kg of traditional bread falls between 32.25 and 35.88 MJ. More than 60% of this value is attributed to renewable resources of water used in irrigation during the wheat farming stage, while over 35% is linked to non-renewable fossil resources, primarily due to the consumption of natural gas in bakery operations. To assess the potential decrease in environmental emissions, a sensitivity analysis was performed, considering the effects of substituting natural gas with biogas and grid electricity with photovoltaic electricity in the bakery. Then, three improved scenarios were developed, each demonstrating effective reductions in environmental impacts, with the most remarkable decreases observed in marine aquatic ecotoxicity (55%) and fossil fuel depletion (44%). Overall, the findings demonstrate that Sangak bread production exhibits a more environmentally friendly profile than other types of bread. These results can guide decision-makers in the bread production industry towards implementing sustainable practices that prioritize resource efficiency and environmental conservation. Also, stakeholders can develop strategies to reduce the environmental impacts and work towards a more sustainable future.

Comparison of the cumulative exergy demand of phase change and reverse osmosis desalination plants with environmental impacts approach

In the scope of the current study, an investigation into the cumulative exergy demand index was conducted for freshwater production across multiple distillation technologies. These technologies encompassed Waterfall Cascading Distillation with Linear Parabolic Solar Concentrator (WCDLPC), Distillation with Linear Parabolic Concentrator and Vacuum Pump (DLPCVP), Distillation with Stand-Alone Point-Focus Parabolic Solar Concentrator (DSPPC), Reverse Osmosis with Non-renewable Energy (RONRE), and Reverse Osmosis with Solar Renewable Energy (ROSRE).The functional unit was established as the production of one ton of freshwater using various desalination technologies. The Outcomes of the analysis pertaining to the cumulative exergy demand in diverse saline water desalination technologies revealed notable findings. Specifically, in the Reverse Osmosis Desalination System with the Conventional System as well as in other desalination technologies (ROSR, WCDLP, DLPCVP and DSPPC), the electricity factor and the photovoltaic panel factor respectively exhibited the most substantial contributions to the cumulative exergy demand. Remarkably, it was observed that the RONRE technology exhibited the highest cumulative exergy demand, reaching 107.04 MJ, while the ROSRE technology demonstrated the lowest demand at 5.98 MJ. Furthermore, the integration of renewable solar energy in lieu of non-renewable electricity within the reverse osmosis technology exhibited a remarkable reduction in cumulative exergy demand, achieving a reduction of 17.90 times. Similarly, the substitution of the waterfall cascade system with a vacuum system in the WCDLPC technology resulted in a 2.69 times reduction in cumulative exergy demand.

Environmental damages, cumulative exergy demand, and economic assessment of Panus giganteus farming with the application of solar technology

The use of photovoltaic (PV) technology in agricultural production can mitigate the environmental impacts of mushroom farming. However, changes in the environmental impacts and economic benefits of the application of PV technology are still unclear. Thus, we evaluated the environmental impacts, energy flow, and economic aspects of mushroom (Panus giganteus) farming systems without solar PV (WS) technology and with PV technology from the generation of substrate materials through harvesting. In addition to a 27 % increase in terrestrial ecotoxicity, P. giganteus farming with PV technology reduced all impact categories by 4–60 %, with a 60 % reduction in CO2 emissions and a 25 % reduction in land resources. These findings highlight the importance of combining PV technology with mushroom farming in agricultural carbon reduction and the efficient use of land resources. In terms of the climate change impact, the PV system reduced CO2 emissions by 2.94 kg CO2 eq./kg of mushrooms compared with the WS system, wherein the aspects of substrate transformation, spawn running, and cultivation were reduced by 78.27–89.91 %. The cumulative exergy demand (CExD) analysis showed that P. giganteus farming combined with PV technology reduced the total CExD by 48 %. With the application of PV technology, the top contributor to the total CExD of mushroom farming shifted from electricity to transportation throughout the supply chain. The PV system reduced costs by 22.09 % and increased the total revenue by 22 % and the cost-benefit ratio by 50 %. Halving the transportation distances of substrate materials and performing localized substitution of wood chips resulted in a 3–34 % reduction in the environmental impacts category and a 23–30 % reduction in nonrenewable fossil energy consumption. These results showed that improvements helped optimize the environmental performance in terms of carbon reduction and energy mixing. Thus, combining PV technology with greenhouse mushroom farming can improve trends in energy and environmental damage.

Assessing resource depletion of NCM lithium-ion battery production for electric vehicles: An exergy-based perspective

Electric vehicles (EVs) play an important role in the low-carbon transition of transportation, and lithium-ion battery (LIB) is a key component of EVs. Because of the high demand for energy and critical metals for LIB production, it is necessary to quantify the associated resource consumption intensity from multiple perspectives. In the present study, the exergy derived from the second law of thermodynamics was applied to assess the abiotic resource depletion associated with lithium nickel cobalt manganate (NCM) battery production, including NCM111, NCM523, NCM622, and NCM811. For comparability of results, the functional unit was defined as 1 kWh NCM power pack. The results showed that the cumulative exergy demand (CExD) value of the NCM523 pack production is 2857.56 MJ/kWh, with the cathode material manufacturing process accounting for 56.77% because of the significant contribution of CoSO4. The CExD of battery production can be effectively reduced by reducing cobalt use and adding a solvent recovery device. The supply stage of upstream raw and auxiliary materials is the key to CExD reduction. The comparison results indicated a significant reduction in the CExD of Ni-rich NCM batteries due to improvement in energy density and reduction in cobalt demand. In addition, the comparison of abiotic resource depletion characterization results and method characteristics among the CExD, ReCiPe, and CML-IA methods showed that using CExD has clear advantages with regard to objectivity and long-term stability in the evaluation of rapidly innovated battery products. Applying exergy-based accounting methods for resources contributes to a scientific understanding of abiotic depletion levels and improves resource efficiency in the relevant industries.

Production of chemicals and utilities in-house improves the environmental sustainability of phytoplankton-based biorefinery

Life cycle assessment was used to evaluate the environmental impacts of phytoplanktonic biofuels as possible sustainable alternatives to fossil fuels. Three scenarios were examined for converting planktonic biomass into higher-value commodities and energy streams using the alga Scenedesmus sp. and the cyanobacterium Arthrospira sp. as the species of interest. The first scenario (Sc-1) involved the production of biodiesel and glycerol from the planktonic biomass. In the second scenario (Sc-2), biodiesel and glycerol were generated from the planktonic biomass, and biogas was produced from the residual biomass. The process also involved using a catalyst derived from snail shells for biodiesel production. The third scenario (Sc-3) was similar to Sc-2 but converted CO2 from the biogas upgrading to methanol, which was then used in synthesizing biodiesel. The results indicated that Sc-2 and Sc-3 had a reduced potential (up to 60 % less) for damaging human health compared to Sc-1. Sc-2 and Sc-3 had up to 61 % less environmental impact than Sc-1. Sc-2 and Sc-3 reduced the total cumulative exergy demand by up to 44 % compared to Sc-1. In conclusion, producing chemicals and utilities within the biorefinery could significantly improve environmental sustainability, reduce waste, and diversify revenue streams.

Cradle to gate environmental impact assessment of the Iranian forestry operations

This study conducts the first cradle-to-gate life cycle assessment (LCA) study on forestry operations in Iran and provides comprehensive regionalized life cycle inventory (LCI) data on the Iranian forest sector. This LCA employs midpoint and endpoint impact categories based on the IMPACT 2002+ method in addition to the cumulative exergy demand (CExD) indicator. The results of this study show that fuel consumption in harvesting machinery and fertilizer application in reforestation are two sources of direct emissions that contribute to different environmental impact categories. Transportation is the main hotspot in most midpoint environmental impact categories, such as global warming, or endpoint categories, such as human health. The total exergy removed from nature to produce 1 t of wood as logs is about 978 MJ-eq, accounting for 7.7% of the energy content in 1 t of wood. The global warming impact category equals 58 kg CO2-eq or 5.4% of the total CO2-eq contained in 1 t of wood as logs. The environmental performance of the system could be improved by expanding local clients rather than clients from other regions and upgrading inefficient machinery. Gains are also possible by conducting a comparative LCA analysis of different adaptable forest management strategies and harvesting methods compared to the business-as-usual approach in the Iranian forestry sector.

Life cycle assessment, life cycle cost, and exergoeconomic analysis of different tillage systems in safflower production by micronutrients

In recent decades, one of the biggest challenges facing agriculture has been sustainability. To achieve sustainability goals, it is necessary to consider the compatibility of environmental, economic, and energy aspects. The main aim of this study is to conduct an environmental-economic-exergy assessment of safflower production under different tillage systems with Zn and Fe micronutrients using life cycle cost (LCC), life cycle assessment (LCA), and exergoeconomic analysis. For this purpose, three scenarios are evaluated: conventional tillage (Sc-CT), reduced tillage (Sc-RT), and no-tillage setup (Sc-NT). The LCA method ReCiPe2016 is used to assess environmental impacts based on one ton of safflower seeds as a functional unit. In addition, the emissions social cost (ESC) is considered as a hidden part of LCC in safflower production. Finally, a combination of cumulative exergy demand and net profit is used to compute an exergoeconomic index in agriculture as a novelty. Results indicate that On-Farm emissions derived from nitrogen and diesel fuel are the most significant contributor, accounting for over 50% of the impact on human health and ecosystems. Sc-RT with 62.62 Pt and Sc-NT with 71.66 Pt are the best and worst LCA scenarios of this study. Sc-CT has the highest ESC, with 51.14 $, and Sc-NT has the lowest LCC, with 380.39 $. Exergy results show that nitrogen fertilizer has the largest share of cumulative exergy demand, and Sc-RT, with 0.073 $ MJ−1, is the best scenario from an exergoeconomic perspective. In summary, Sc-RT, Sc-CT, and Sc-NT are ranked first, second, and third, respectively, from an environmental-economic-exergy-friendly point of view.

Joint life cycle assessment and data envelopment analysis for the benchmarking of energy, exergy, environmental effects, and water footprint in the canned apple supply chain

The present investigation is designed to analyze the energy consumption rate, cumulative exergy demand (CExD), water footprint, and environmental impacts in canned apple production using life cycle assessment (LCA) technique. Data envelopment analysis (DEA) was also used to identify effective measures in increasing apple orchard efficiency. The needed information was collected through questionnaires and face-to-face interviews in 2020 in the West Azerbaijan state of Iran. The result showed that energy consumption in apple production was 60,026.48 MJha−1. According to the DEA findings, the efficiency of apple orchards in the research area is low, and micronutrients and phosphate have the most potential to reduce. Furthermore, the number of efficient units based on technical performance, net performance and performance scale were 35, 93 and 35. There is a potential saving of 6073.15 MJha−1 of energy. Economic indices such as net return, benefit-to-cost ratio, and investment productivity were 3391.99 $ha−1, 1.75, and 6.003 kg$−1, respectively. The results of LCA+DEA illustrated that abiotic depletion has the greatest potential for reduction among environmental indicators, with a reduction rate of 35%. CExD outcomes determined that the rates of non-renewable fossil (812.16 MJt−1) for apple gardens mostly come from nitrogen and diesel fuel.

A Study of Modern Eco-Friendly Composite (Geopolymer) Based on Blast Furnace Slag Compared to Conventional Concrete Using the Life Cycle Assessment Approach

By posing the question of what will be the definition of sustainable development in the future, it can almost be seen that the principle of “no waste” and the production of new materials with less of a negative environmental impact will have a high priority. To further develop environmentally friendly materials, it is necessary to know about the environmental drivers of new materials as well as to evaluate the environmental effects of conventional materials in construction. According to the definitions of sustainable development and sustainable materials, materials with characteristics such as having low energy consumption, sufficient durability, good physical and chemical properties, while simultaneously reducing pollution should be used. Geopolymer materials may be a reasonable option. In this research, two production processes based on blast furnace slag and ordinary concrete (Portland cement) for one cubic meter of geopolymer concrete have been investigated. To investigate, inputs (materials and energy) and outputs (relevant environmental pollutants) of both systems were determined and a life cycle assessment (LCA) was measured using the Center of Environmental Science of Leiden University (CML) and cumulative exergy demand (CED) quantification methods of SimaPro V.9 software. The results showed that the production system of one cubic meter of conventional concrete has maximum environmental effects in all classes except in the destruction of the ozone layer, and the system of producing one cubic meter of geopolymer concrete based on slag has much less environmental effects than the normal concrete system. It also consumes 62% less directly during its lifetime. As a result, geopolymer concrete may be a suitable alternative to traditional concrete as a sustainable material.

Machine Learning Models of Exergoenvironmental Damages and Emissions Social Cost for Mushroom Production

Applying conventional methods for prediction of environmental impacts in agricultural production is not actually applicable because they usually ignore other aspects such as useful energy and economic consequence. As such, this article evaluates intelligent models for exergoenvironmental damage and emissions social cost (ESC) for mushroom production in Isfahan province, Iran, by three machine learning (ML) methods, namely adaptive neuro-fuzzy inference system (ANFIS), artificial neural network (ANN), and support vector regression (SVR). Accordingly, environmental life cycle damages, cumulative exergy demand, and ESC are examined by the ReCiPe2016 method for 100 tons of mushroom production after data collection by interview. Exergoenvironmental results reveal that, in human health and ecosystems, direct emissions, and resources and exergy categories, diesel fuel and compost are the main hotspots. Economic analysis also shows that total ESC is about 1035$. Results of ML models indicate that ANN with a 6-8-3 structure is the optimum topology for forecasting outputs. Moreover, a two-level structure of ANFIS has weak results for prediction in comparison with ANN. However, support vector regression (SVR) with an absolute average relative error (AARE) (%) between 0.85 and 1.03 (based on specific unit), a coefficient of determination (R2) between 0.989 and 0.993 (based on specific unit), and a root mean square error (RMSE) between 0.003 and 0.011 (based on specific unit) is selected as the best ML model. It is concluded that ML models can furnish comprehensive and applicable exergoenvironmental-economical assessment of agricultural products.

Marine shell-based biorefinery: A sustainable solution for aquaculture waste valorization

Fossil-derived products contribute significantly to greenhouse gas emissions. Transitioning from fossil-based to bio-based products is an effective solution to this problem. There has been substantial research on how biorefinery systems can help achieve such an aim. Marine shell-based biorefinery systems have been proposed in the past, but their environmental sustainability has not been empirically proven. So, the current study examines the environmental impacts of chitosan production as a promising biomaterial in a lobster shell-based biorefinery. The life cycle assessment approach is used to estimate the environmental impact and cumulative exergy demand of chitosan production. The present study also aims at environmentally scrutinizing two non-commercial scenarios, i.e., the replacement of sodium hydroxide with potassium hydroxide (labeled as Scenario 1) and chitosan production based on the biological extraction of chitin and the replacement of sodium hydroxide with potassium hydroxide (labeled as Scenario 2) against the conventional chitosan production (labeled as the Base Scenario). The findings show that 1 kg of conventional chitosan production in the developed biorefinery leads to 8.75E-05 DALY damage to human health and 2.60E+02 PDF.m2.yr damage to ecosystem quality, mainly due to chitin and sodium hydroxide. In comparison, chitosan production based on Scenario 1 and Scenario 2 can lead to a 17% and 23% reduction in damage to human health and 6% and 11% in damage to ecosystem quality, respectively. The developed biorefinery produces chitosan with a weighted environmental impact of 43 EUR2003, which can be discounted by 8% and 13% using Scenario 1 and Scenario 2, respectively. The findings indicate that chitosan production eliminates 2.32E+02 MJ/FU exergy from nature, that approximately 54% of it is related to the “non-renewable, fossil” category. Scenarios 1 and 2 correspond to approximately a saving of 13% and a growth of 71% in exergy removal from nature than the Base scenario, respectively.

An optimised solar-based microgrid integrated with desalination to enhance exergy sustainability

The size of a solar microgrid system should be designed based on aspects of sustainability, such as cost, exergy, etc. This study by the division algorithm finds the optimal size with maximum reliability vs. the cumulative exergy demand. Larak Island, Iran, is used as an example of how the concept could be applied to the real world. According to the introduced optimal size, 1 m3 of freshwater generated by the solar energy system leads to an average cumulative exergy demand of 17 MJ. While integrating a diesel generator into system means, exergy demand reaches 33 MJ/m3 of freshwater.

Life Cycle Assessment of NPK Fertilizers in Rice Production in Northern Iran

Life cycle assessment is an appropriate method to study the environmental impacts of producing a crop product throughout its cycle in a production system. Therefore, this research was conducted with the aim of evaluating the life cycle of paddy rice production under the effects of NPK fertilizers in Mazandaran province in northern Iran during 2017-2018. The different doses of nitrogen (N), phosphorus (P) and potassium (K) fertilizers were N250P150K150; N200P100K100; N150P75K75; N100P50K50, and control (N0P0K0). The results displayed that an average amount of cumulative energy demand and cumulative exergy demand was 11549.78 and 13443.08 MJ, respectively, that with increase of NPK consumption, both indices showed increasing trend. The average ecological footprint was 1190.80 m 2 a which CO2 emissions had shown the highest effect on the ecological footprint. The average of the impact categories of abiotic depletion was equals 12.44 kg Sb eq, acidification (3.15 kg SO2 eq), eutrophiction (2.33 kg PO4 eq), malodorous air (7295733 m3 air), freshwater sediment ecotoxicity (75.79 kg 1,4 DB eq), marine sediment ecotoxicity (116.11 kg 1,4 DB eq) that all of which enhanced with increasing NPK consumption. The average global warming potential (GWP) 20a and GWP 500a were 399.20 and 382.97 kg CO2 eq, respectively. Two indicators of human toxicity and terrestrial ecotoxicity in the three periods of 20, 100 and 500 years shows increasing amounts equal 0.42% and 140.70% during 20a to 500a, respectively. All pollutants released into the air and the water demonstrated enhancing trend with increasing NPK amounts. The emission of nitrate into soil, metals into the soil, and chemical oxygen demand showed enhancing trend with increasing NPK levels. Therefore, enhancing the emission of pollutants by increasing nitrogen consumption can be due to increase of yield.

Exergo-ecological analysis and life cycle assessment of agro-wastes using a combined simulation approach based on Cape-Open to Cape-Open (COCO) and SimaPro free-software

Thermochemical processes to convert bio-wastes into valuable products and bioenergy have been extensively studied in the literature. Experimental and, to a lesser extent, rigorous simulation papers concerning these processes have been widely considered and discussed in the literature. Nonetheless, there is still a gap to fill in providing a fast and reliable simulation scheme. In this paper, an efficient simulation strategy, combining the free-software COCO simulator for the bio-waste slow pyrolysis coupled with commercial SimaPro code to carry out the Life Cycle Assessment (LCA), was applied. The pyrolysis product yields at 673, 773, and 873 K were well predicted using mass and energy balances and a proposed reaction scheme from the literature. Simulations were validated using experimental data previously reported. The highest yield was 53.7% for biochar (673 K – stalk of white grape), 32% for bio-oil (773 K - marc of red grape), and 56.3% for gas (873 K - marc of white grape). The results from LCA and cumulative exergy demand (CExD) were useful to detect and reduce environmental impacts in previous stages of the process.

Comparative life cycle cost-energy and cumulative exergy demand of paddy production under different cultivation scenarios: A case study

The use of energy efficient in agriculture is one of the important factors to achieve sustainable production in agriculture. Considering the limited resources and the importance of preventing the loss of resources, it is necessary to evaluate investment projects from an economic point of view This study applying life cycle assessment (LCA) of paddy production in Khuzestan province of Iran were studied, LCA is a methodology for assessing environmental impacts associated with all the stages of the life cycle of a commercial product, process, or service. In this study, energy indicators, economic analysis and LCA of paddy production in Khuzestan province of Iran were studied. Paddy production in this province was analyzed under three scenarios of multiple cultivation system including (Paddy-Transplantation System) PTS, (Paddy-Flooding System) PFS and (Paddy- Drying System) PDS. The highest total input (79069.80 MJ ha−1) and output (105400 MJ ha−1) energies are related to PTS method. PDS method has the lowest energy production and consumption. Diesel fuel and nitrogen fertilizers consume a lot of energy. Electricity and water showed 13 % of energy consumption in PFS method. Depending on the type of cultivation in PDS method, human labor has a large share of energy. The results of benefit to cost ratio showed of PTS method (6.60) shows the high profit of rice production from the amount of cost. Categories of damage to human health, ecosystems and resources were reported according to ReCiPe2016 method for paddy production. The resource impact category for PDS (114.76), PFS (111) and PTS (102.60) USD2013 is the highest to the lowest, respectively. The categories of human health damage for PTS, PFS and PDS methods were 0.041, 0.04 and 0.05 DALY, respectively. The resource category accounts for a significant portion of environmental emissions. Results of CExD showed the non-renewable, fossil form has a significant value in PTS (12980.06), PFS (14215.41) and PDS (14544.40) MJ ton–1, also that nitrogen fertilizer and the use of machinery and diesel fuel have the greatest impact on energy forms.

A new method for green forage production: Energy use efficiency and environmental sustainability

In recent decades, hydroponic fodder has been widely used for livestock feed. Studying the energy indicators and life cycle assessment (LCA) of the hydroponic fodder can result in applying the best method for higher production with less environmental impacts. Hence the aims of this study are to evaluate energy and water use and environmental indicators for hydroponic fodder production in central region of Iran. Data collected using oral questionnaire from hydroponic fodder greenhouses in Isfahan province. The results demonstrated that total energy for production of one ton hydroponic fodder is 5060.40 MJ. Also energy ratio (ER) and energy productivity (EP) were calculated as 0.33 and 0.20 kg MJ −1 , respectively. The water productivity (WP) was about 287 kg m −3 which indicates that about 287 kg of forage is produced per each m 3 of water consumed. The results also showed that despite the many benefits of hydroponic fodder on livestock nutrition, its greenhouse cultivation imposes many adverse effects on the environment . Human health damage categories was calculated as 0.00434 DALY t −1 which was much more than other similar products. Cumulative exergy demand (CExD) results showed that the percentage of Non-renewable, fossil for hydroponic fodder production mainly result from electricity which can be decreased via using renewable energy (RE) technologies.

An analysis of energy use and economic and environmental impacts in conventional tunnel and LED-equipped vertical systems in healing and acclimatization of grafted watermelon seedlings

Uncertain climate changes and increasing energy and food production demands lead to food insecurity, especially for drought-prone areas like the study region, Iran. This study assesses the energy use, economic, and environmental impacts of two different healing and acclimatization systems, the conventional tunnel systems (CTS) and the LED-equipped vertical systems (LVS), for grafted watermelon seedlings in Iran. Life cycle assessment (LCA), cumulative exergy demand (CExD), and life cycle cost analysis (LCCA) approaches are used to assess the impacts of grafted watermelon seedlings. The functional unit is one million grafted watermelon seedlings (MGWS). The top findings of this study indicate that CTS increases energy consumption, damage to human health, ecosystems, and resources compared with the LVS. Further, the economic analysis revealed that the net profit in the multi-floored LVS is 24% higher than that of the CTS. In conclusion, LVS is less energy consumptive and environmentally burdensome yet more profitable than the CTS. Notably, the finding from this study supports recommendations that will be useful for industries or producers who need to develop sustainable grafted watermelon or vegetable production systems in Iran or similar regions. Top recommendations include using organic fertilizers , multi-floor LVS, and most importantly, replacing CTS with LVS to promote a sustainable agricultural production system. • Conventional tunnel systems consume more energy than LED-equipped vertical systems. • LED-equipped vertical systems reduce human health and ecosystem impacts. • LED-equipped vertical systems are more profitable than conventional tunnel systems.

Energy-economic-environmental cycle evaluation comparing two polyethylene and polycarbonate plastic greenhouses in cucumber production (from production to packaging and distribution)

Excessive consumption and improper management of inputs would lead to environmental damages, as well as decreased economic benefits. Thus, a thorough examination of the entire production process from the viewpoint of energy flow, economic profit, and environmental effects can identify hotspots and facilitate input management. Accordingly, in the current investigation, energy, economic and environmental aspects of greenhouse cucumber production systems were measured by life cycle assessment (LCA) technique and cumulative exergy demand (CExD) analysis by considering different greenhouse structures. Furthermore, the data envelopment analysis (DEA) approach was used to determine the efficiency of manufacturing units and optimal consumption pattern. The information required was acquired through interviews and questionnaires with 35 greenhouse owners, and consultation with greenhouse enterprises in the Khuzestan province of Iran. Based on the findings, energy consumed was 6626.45 MJton−1 in Sc1, and 6410.32 MJton−1 in Sc 3. The findings of benchmarking revealed that boosting the efficiency of the crop production process can lower input energy by 14.80%. The energy consumption for the construction of the first and second type of greenhouses was calculated to be 14,811.13 and 17,541.73 MJ (1000 m2)−1, respectively. With regard to the production variable costs, chemical fertilizers and labor had the largest contributions to the total expenses, at 7.6 (15.41%) and 7.87 $tonne−1(15.94%), respectively. In the evaluation of the energy and economic indicators, the combined indicator of Energy Intensiveness for the first and second types of greenhouse systems was found to be 80.26 and 77.07 MJ$−1, respectively, indicating higher energy-economic productivity of the first type of system. Based on LCA results, direct emissions due to input consumption (air: carbon dioxide (CO2), and nitrogen oxides (NOx); soil: mercury (Hg), copper (Cu), and lead (Pb)), and indirect emissions induced by chemical fertilizers, greenhouse structures, and chemical pesticides production are the environmental hotspots.

Environmental Assessment of Austrian Organic Dairy Farms With Closed Regional Production Cycles in a Less Favorable Production Area

Extensive dairy production in less favorable production areas has a long tradition in Austria. Nevertheless, dairy production also contributes considerable environmental impacts (EIs), e.g., greenhouse gas emissions, nutrient losses, and land use. Therefore, 20 organic dairy farms located in the Lungau region in Austria were assessed concerning their EIs via life cycle assessment (LCA). Cumulative exergy demand (CExD), normalized eutrophication potential (EP), aquatic ecotoxicity potential (AE), and global warming potential (GWP) were considered as impact categories to describe the farms' EIs. The farms were part of a pilot project aiming to produce high-quality dairy products and keep production cycles closed within the project region. Consequently, the purchase of key off-farm resources was only possible within the project region. We adapted existing life cycle inventories to account for those regional resource purchases. Subsequently, the EIs of the 20 farms were related to the functional units (FUs) of 1 kg energy-corrected milk (ECM) and 1 ha agricultural area for milk production and compared to a representative model dairy farm (MDF) that was created based on statistical data and average production values of organic Austrian dairy farms. Compared to the MDF, results show an ~58% lower EP per ha and 44% per kg ECM of the Lungau farms. Further, the CExD per ha was about 24% lower due to a lower use of resources caused by the lower production intensity of the Lungau farms. Regarding GWP, Lungau farms are favorable considering 1 ha as the FU, whereas the MDF seems advantageous if 1 kg ECM is used as the FU. However, caused by a high variation of purchased roughage and the lower production intensity, the Lungau farms cause higher AE, regardless of the FU. Overall, we identified three principal production parameters determining the environmental performance of milk production in a closed production cycle in a less favorable area, namely, (1) the stocking rate, (2) the fed concentrate, and (3) the purchased roughage. Using those inputs at moderate intensity, the extensively managed Lungau farms can competitively contribute to producing food, thus highlighting the importance of site-adapted agriculture.

Characterization and Life Cycle Exergo-Environmental Analysis of Wood Pellet Biofuel Produced in Khyber Pakhtunkhwa, Pakistan

Major objectives of this study were to produce low-emitting wood pellet biofuel from selected agro-forest tree species, i.e., Kikar (Acacia nilotica), Oak (Quercus semicarpifolia), and Mesquite (Prosopis juliflora), grown in the southern part of the Khyber Pakhtunkhwa (KP) province of Pakistan using indigenously developed technology (pelletizer machine). Primary raw material, such as sawdust of the selected agro-forest tree species, was obtained from sawmills located in southern part of KP. Life cycle inventory (LCI) was sourced for entire production chain of the wood pellet biofuel by measuring quantities of various inputs consumed and output produced. In addition, the wood pellets were characterized to examine diameter, length, moisture content, ash content, bulk density, high heating value (HHV), low heating value (LHV), as well as nitrogen and sulphur contents. A comprehensive life cycle assessment was performed for wood pellet biofuel production chain using SimaPro v9.1 software. A functional unit of one (01) kilogram (kg) wood pellet biofuel was applied following a gate-to-gate approach. The results of the present study were in accordance with the recommended Italian standard CTI-R 04/5 except for pellet bulk density and nitrogen content. The bulk density for all wood pellets, manufactured from the saw dust of three different agro-forest tree species, were lower than the recommended Italian standard, while for nitrogen content, the results were higher than the recommended Italian standard. Among the environmental impacts, Kikar (Acacia nilotica) wood pellets were the major contributor to fossil fuel depletion, followed by ecotoxicity, mineral depletion and acidification/eutrophication. This was primarily due to lubricating oil and urea-formaldehyde (UF) resin used as inputs in the wood pellets biofuel manufacture. Likewise, human health and ecosystem quality was also affected by lubricating oil, UF resin, and saw dust, respectively. In cumulative exergy demand of 1 kg wood pellets biofuel, the highest impact was from Kikar wood pellets for non-renewable fossils, mainly due to lubricating oil used. Difference in environmental impacts, damage assessment, and exergy were examined in three different scenarios for major hotspot inputs by reducing 20% lubricating oil in case 1, 20% UF resin in case 2, and without usage of UF resin in case 3, while marked reduction was observed in ecotoxicity, fossil fuel, and mineral depletion, as well as acidification/eutrophication impact category. Moreover, a pronounced reduction was also noted in the non-renewable fossil fuel category of cumulative exergy demand of one kg of wood pellets biofuel produced.